Ho-Oh, Lugia, Moltres, Articuno, Zapdos, Raikou, Suicune, Entei, Mewtwo, Groudon, Rayquaza and Latios. Possibly others.
Moltas: the fire legendary bird Pokemon the second strongest bird Pokemon
Well, I guess you mean "Soul Silver", and the main legendary Pokemon is Lugia, Water/Flying-Type.
You can't breed legendary Pokemon eggs on Pokemon SoulSilver or on any Pokemon game.
the only legendary that you can breed is manaphy. and that will result in a phione.
Latios
They will simply gain Exp. You can't breed legendary pokemon.
It might depend on the Pokemon, though usually you can face legendary Pokemon again if you beat the Champion.
it is impossible except for when you have cheats in Pokemon pearl,platinum,diamond
no
over 9000
to find lugia go to the 4 whirl islands
No the only exeption is spiritomb only it can lay eggs